Continuous hydrogenator



Aug 29, 1950 v. MILLS ETAL 2,520,424

CONTINUOUS HYpRoGENAToR Aug. 29, 1950 v. MILLS ETAL 2,520,424

CoNTINUOUS HYDROGENATOR l Filed May 2, 1947I 2 Sheets-Sheet 2 Patented Aug. 29, 1950 `"Victor Mills, JudsonH. Sanders, and Harold K. Hawley, Cincinnati, Ohio, assignors to` The Procter and Gamble Company,

a corporation of Ohio Ivorydale, Ohio,

y application May 2', 1947, seriaiuo. 745,662

This invention relates to apparatus suitable for use in continuous hydrogenation of unsaturated liquid substances, i. e., for addition of hydrogento carbon to carbon double bonds in a continuous process.

An object of the invention is to provide such intense agitation in the hydrogenation chamber of apparatus of this character as to permit the reaction to be carried out at an exceptionally rapid rate, thereby effecting economies in operation and improvements in the quality of the product.

Another object is to provide means of removing from the liquid undergoing hydrogenation the heat of reaction as fast as it is liberated, thereby enabling the reaction rate to be kept relatively constant as the liquid progresses through the hydrogenation chamber, thus facilitating control of the desired end point of the reaction.

Another object is to provide means of preventing channeling of unhydrogenated liquid to the outlet of the hydrogenation chamber, thereby avoiding contaminating the finished hydrogenated product with ravv or incompletely processeci material.

Another object is to provide a complete assembly of apparatus particularly adapted to continuous hydrogenation of unsaturated liquid materials in a practical and easily controllable manner.

Other objects are to provide the foregoing features in apparatus of sound engineering design, suitable for economical commercial use.

The apparatus of the present invention is designed for continuous hydrogenation of unsaturated materials such as higher fatty acidsand their esters, particularly unsaturated natural glyceride oils, in that form of practice which employs a continuous liquid phase with dispersions of iinely divided catalyst and of hydrogen gas throughout this liquid phase. Continuous hydrogenation processes which `may be carried out in the apparatus of the present invention are de` scribed and claimed in applications Serial No. '745,660 and Ser. No. 745,661, filed concurrently herewith by Mills, Sanders and Hawley.

Two forms of hydrogenators which meet the requirements of our invention, together with a flow chart of a hydrogenation system employing such hydrogenators, are illustrated in the accompanying drawings, in which f Figure 1 is a schematic licw chart showing the principal elements of a typical continuous hydro-1 genation system; v i

Figure 2 is a side elevation of a mechanically agitated continuous hydrogenator vessel;

4 Claims. (Cl. 23-285) f i 2 Figure 3 is a vertical section of the vessel shown in Figure 2; i

Figure 4 is a horizontal section of the vessel,`

taken on the line 4--4 of Figure 3;

stators, and oneof` the horizontal bales;

on'the `line 6-2-6 ofFigure; 2

Figure '7 is-'a fragmentary i elevation, partly Figure 6 isa fragmentary -sectional vievv taken section, illustrating "a modification of the agitator shaft and bladestructure;andr H Figure 8 isahorizontalsection taken on the une 3 8 of'Figure 7',

The several elements ofapparatus indicated schematically-in Figure Land their respective purposes andfunctionsaspart oi a complete` continuous hydrogenaticn system, will be under-` stood from the 'following description of -a pre-`V ferred mode of carryingout the process. The unsaturated liquid material to-be hydrogenated is delivered from supply `tank I Il by means of pump `I 2 through a tubular -preheater I3 to and' through the hydrogenator I4. A suitable hydrogenation catalyst suspended in ar small `quantity of a suitable' liquid (which may often be a portion ofthe material tobehydrogenated) is delivered from catalystsupplytank l5 by 'means of pumpL I6 either directly into the hydrogenator, or (as shown) in to the' pipeline `which is delivering the main supply of material to be hydrogena'ted from the' preheater to the 'hydrogenaton for example, at point Il. A continuous supply of hydrogen, or a suitable hydrogen-containing gas, is introduced into the same pipeline at' another point ahead of the hydrogenatonfor `example `at point i8, the hydrogen 'supplybeing drawn from` a suitable reservoir or supplmasillustrated at l 9, by means of compressor 2li-through a: pressure `regulating valve 2 l. While `flowiifig through the hydrogenator 14, the m'iXtureofthe -liquid material to be hydrogenated, lthe catalyst, andthe hydrogen isV subjected to-violent agitationto bring these three materials into intimate contact with one another` and to bring about a rapid movement of the individual particles yof each of the non-liquid phases in Contact with the particles of the liquid phase, thus promoting a high velocity ofthe hydrogenation reactions Whichuoccur in this vessel. The

through the top of small tank,2e5. Thefliqui'd Y outlet of this tank is provided with a iloat valve adapted to close this outlet against the discharge of gas. The hydrogenated material leaving the hydrogenator is cooled by means of heat exchanger 26, and any remaining gas which has eeneeui. ef eelriigesubeeeeeni ,te the .digen in pressure at valve 213 is then separated. from the hvdreeerieied, materiel @smell tefnk .2t and the catalyst is removed `from the oil, for example by means Qfiheflier '2t ...The hydrogenetor, I4 ...er 'the .system ius 'd- Seribeei. mer/.be constructed es Shown elre Deir.- ticularly inrFigures 2y to ,6, inclusive, in'whi'ch is illustrated e preferreiyae, f...h.ys1l1"ee`eeetiie apparatus. Thus the hydrogenator may comprise en einer .,Jeekei. 3.0, prende@ with. .er1 exbe'eieh eeuwige. 3l te relieve seuee'd liv, tempereture changes, and an innercylin'der 32, the jacket and cylinderudening van vanrnil'ar` space 33 within which is circulated a huid coolantatheinlet and outlet conduits forvthe coolantbeing shown in Figure 2 at` 35iy andr 35 respectively 4Ai'lwhllow shaith, of substantially less 'diameter than cylinder 32 is disposed, coaxially within the cylinder and supported for'rotatinabout fveritiea1 axis, shaft as and cy1indern3'2-dfng "an annular reaction passage. ill which the 'mixture Qfjheiiquid fatty matefiarthe 'h r'og m,y ,A theecatalytic agen`t,.i2 s intenselya tated fwhile howling in an upward direction, being introdued through an inlet passage. 39 forindhin 'anlrlplate l0V atftlie lowerfend `of cylinder 32, and kdischargir'ig. thr'igha'n outlet [passage 12 'in an yanl'llar plate A3 4at the 'uppl idyf y Cfylllirider f ,he hydrogenatorf, a ,cap structure comprisingplate 3 and c members v45 andlB, the several part'sbeirig l tgetiiger as shownjmere partieuiany 'in Fgiirege. A, radijaifthrust bi mg da seateql'in hesiter 45 and Vretained in on inemblydi engages eed Supports 'e Shaft 48 which 'exten ,e with@ aaiseeeured .to ire..h01.1w.s'he.fiee regen ihe..;1etier is .J'eereeled-.fr reta .1'1- e R'eee'ved weiland Seemed. to @has e e rs. ieee ie,.a.eeup1ine element. '.-il .le dri @heft 12, dLiS.- pesefl eeexielly f Shaft .38%. extends with@ elia is. Secured for ,rete-inutile Coupling-...element pil Drive. Shaft 52., is .Jeiilneledfer I'Qi'etiee in., 'the Sametime .bese etruetgre indie. tedeereellvee 53.. the hvdreeeneter beine. euiieblv l gullies, tf1 this: Das? Structures .AIlQ fkhallg ,Shff 55....f1rives Shaft. 5.2 fihreueh .beve1..,eee,ri.r.1sr5l. whereby .thehelleweheft 38de reieiedrepidlv; variable speed. searing inerte irieerporeied in the `:motorhousing ,.innrder. that thesneedef the shaft may be appropriately,.seleeted,...lt.will be 'appreciated thatthedetails of this construction may be varied Widely.

The. annular reactionpassage between shaft 38 and cylinder 32 is divided into a series of compartments or reaction zones by means of a plurality of horizontally disposed annular disks or baffles 6i), the baffles being spaced longitudinally of the hydrogenator. The outer diameter of each baie $0 is such that the baiiies t snugly within cylinder 3 2, theqinnert ldiameter, being slightly largerrthan the Vouter diameter ef shaft 38, so as to aiord slight mechanical clearance therebetween. The reacting materials flowing upwardly are thus caused to flow through the restricted 'annular passages dened between shaft 38 and bailies 6U in moving from each compartment or reaction zone to the next higher lione, retention of th'e materials in each zone for a y,substantial length of time being assured. AVChanneling, or too rapid movement of "insuiciently reacted materials through and out of thek hylrogenator, is thereby avoided. The baiiies may be retained in proper spaced relation by a `series of spacing sleeves, the (several Sleevestting snugly within cylinder 32 so that each of the bales is 'clamped between an adjaf c'e'nt pair of ysleeves `6l. Each of the sleeves' 6i may be formed with longitudinally extending slotsBZ, as shown more particularly in Figures 3 a'nd '5, to reduce theweight of the sleeves and to: increase the heat transfer surface `and the volume and [capacity of the several reacting zones.` An efficient hydrogenator may be provided with as many as 11 baffles, `orv even more, so as 'to provide l2 or more reacting Zones, but th'e number of zones lmay Vbe varied widely. e

It `vfvill be appreciated that while baffles l are cfri've'niently 'mounted on the cylinder '32,` they may be mounted, if desired, on shaft 38, clear'- alncefor the passage yof liquid being aorded between the periphery of the baifles 'fillA and the cylinder 32. The structure shown in the drawings is preferred, however, since the retarding ele'ct on the axial ow 'of liquid is greater.

, In order 'to effect intense agitation Yof the-nia teral, each zone may be provided with a series of agitator blades 65, and with cooperatingstaf tor` blades or stationary bailes 66 located `'above and 'below 'the agitator blades. The 'agitator blades' are disposed radially of and are bolted securely tothe hollow shaft 38 in circumferentially spaced relation, Yone such series of agi'- tator blades being4 shown in dotted lines in Figurfl', Y In 4order `to prevent leakage of t'he reacting Imaterials Ipast 'the securing b'oltsr'toA the interior or the Yshaft'38, a 'sleeve 68 extending aft 38, l'is fwelded to the la'tte'r ateach T1 s e ir'cimfefnnaily 'spaced statorgbiadesfss ""wisedisposedradiallyk Q fthje axis fr shaft vare bolted oriar'e'tlerwise'seciired to the sleeves v(il adjacent Ato Veach'o'ffthe 'airiila'r dislgsrfp, preferably intermediate 'the slots 62 formed sleeve Bil, Aas shown in ligi.v ltfvvill be ptsfved thateach ,reaction Zeile is 'brei/'idea With'cjne :series of agitator 'blades 55 Aand "two "series` ofgcoperating lstator blades 66, the 'latter acting to resist continuousl swirlingfmovemert of the4 reacting materials `:about shaftfi' `and'otlierv vise serving :to increase the degreeof agitation imparted to the materials.l Preferablmublades and 'V6/6Min adjacent seri'esv are so Adirnensicried as to afford only the necessary mechanical 'clearf einge. .between @eeh eihel. similarly. 'nlv rifeeheileel eleefeneeie efferiie@ between the. S-ietor blades 66 and the shaft 38 andgbetweenithle eeitetorblades 6 5. end. the 'sleeves ,61..- Ae 13u19 We prefer. te emploie-tei@ hledeerreieeiigg in:

Wardly from the wall ci the vessel at least B5 percent of the distance from wallto shaft, and similarly to employ agitator blades extending outwardly fromthe shaft at least 85 per cent of the distance fromshaft towall.` i

In the particular hydrogenator illustrated, `we eieotively avoid undue contamination `of `the nished product with raw oil or withinsuiiciently hydrogenated oil by a combination of two provisions: First, the relatively long passage through which the reaction mixture passes on its way from the entrance to the exit oi the hydrogenator, the flow through this passage being interrupted repeatedly by a series of transverse agitators separated by a corresponding series of i stator blades tending to break` up swirling induced by l;

event. channeling of insufficiently hydrogeni ated` material to the outlet is to a large extent avoided, although not to the full extent preferred for some purposes, when the length ofthe chamber from inlet to outlet is such as to permit the employment of at leastlO to lseparate setsof i" agitators, each set separated from the next by a cooperating set of stator blades.

By providing the mechanical `agitation in a direction which is predominantly transverse (preferably perpendicular or even somewhat counter) to the main direction of oW of the liquidbeing hydrogenated, the agitator-impelled transfer of unprocessed raw material towards the outlet 'of the vessel is minimized. This may beaccomplished by aligning the pressure resisting surfaces of the agitator blades and of the stator blades so that they face in a direction generally transverse to, and not tending towards, the general direction of liquid flow. While the blade surfaces thus define planes substantially parallel to the general direction of liquid flow, slight inclination is of course permissible, and inclination tending to retard axial flow may in some cases be desirable.

`When the chief reliance for the avoidance of ,fchanneling is placed in horizontal baiiles such as elements Bil, with a minimum of agitator blades-i. e. when each of the lesser zones betwentwo horizontal bailies is provided withjust one set of transverse agitators--channeling is to a large extent avoided, although perhaps not l to the full extent preferred for some purposes, by thus subdividing the hydrogenation space into at least six lesser zones. The interconnecting passages between the lesser reaction zones of the hydrogenation chamber are preferably so greatly restricted in cross-sectional area that the agitation occurring in one of these zones is not felt to an appreciable extent in the adjoining zone. Our circular baffles, 69, which in a preferred case leave an annular passage around the shaft just one eighth of an inch wide in a hydrogenator having an internal diameter of 8 inches and a shaft diameter of 4 inches, accomplish this purpose.

The hydrogenator used in our process is designed to provide for efficient removal from the reactants of large quantities of heat, since the heat generated by the reaction amounts to about 2 B. t. u. per pound of oil hydrogenated per unit of iodine value drop. In the hydrogenator illustrated in the drawings, `the heat transfer surface is large in relation to the cubical contents of the vessel, and the heat transfer coeiiicientis `high because of the violent agitation.

A very high degree of agitation is provided in the hydrogenator illustrated by the cooperation of the moving agitator blades and the xed vertical battles. Preferably the clearance between these blades and bales does not exceed about three sixteenths to one fourth of an inch, and the preferred speed of the outer edges of the rotors is of the order of 6 feet per second. The use of xed vertical baffles, or stators, A,to retard the swirling action of the liquid, which would otherwise be induced by the rotating agitators, is important particularly in order to avoid a centrifugal eifect which would tend to move the suspended catalyst towards the outer walls of the vessel and would simultaneously tend to move the gas bubbles towards the center of the vessel.

In Figures 'l and 8 is shown a modified form of the invention in which the agitator shaft `l38 is solid. This permits a decrease in the shaft diameter and a corresponding increase in the horizontal cross-sectional area of the free path traveled by the liquid in moving from the entrance to the exit of the hydrogenation chamber, without increase in the diameter of the vessel. In this modification the agitator blades I E5 areV formed integrally with a sleeve |10, the sleeve bein-g di,- mensioned to t snugly on the shaft and being retained thereon by bolts I'H. Radial ns |12 are provided, these ns serving to retard` axial now of liquid and to reinforce and strengthen the agitator structure. It will be observed that four blades are shown; the same number of blades may be employed in each of the adjacent stator units, but the number of stator blades may be greater or less; When using this form of vessel channeling is quite effectively prevented when the hydrogenation zone is subdivided. into 12 lesser zones by means of horizontal bailles i60, although fewer than this number will sufce when substantially complete avoidance of contamination of the finished product is not required.

It will be appreciated that many variations from the design of apparatus illustrated in the accompanying drawings may be employed without departing from the spirit or scope oi?` the invention. Thus, the oil and catalyst inlet may be placed near the top of the hydrogenator and the oil and catalyst outlet at the bottom, with the hydrogen inlet remaining near the bottom, a design Which may be employed to advantage when the complete saturation of the oil is desired. Another modication is to mount the hydrogenator horizontally instead of substantially upright, in which case each or baffles 60 (now vertical) is provided with an opening along its upper edge to permit passage of hydrogen along the length of the Vessel.

When employing the apparatus herein illustrated and described under typical hydrogenation conditions, with the flow of liquid, suspended catalyst, and hydrogen passing at uniform rates in contact with one another through the reaction Vessel under conditions of extreme turbulence, the temperature of the liquid is established at a chosen value by adjusting the pressure of the steam or the temperature and rate of flow of other heating medium through the jacket of the liquid preheater, and this temperature is maintained with but little or no rise as the liquid passes through the hydrogenator by controlling the temperature or rate of flow of die 'water er other cooling medium through the jacket surrounding the llydrogenator` When a relatively small 'overall iodine vfalue drop is being brought about "and consequently the heat liberation is small .in amount, it `may not be necessary 'or desirable to rei-nove more than about two tnlir of the heat Yof reaction, although when th 't'tfal iodine valu-e -drop is l0 units or more we prefer 'to ke'efp the temperature of the liquid prabtic'ally 'constant as it progresses 'through the reaction vessel, with 'a preferred maximum tem'- p'e atu'e i'iSe of not more than 10 to -1'5 -An option to this preferred temperature 'control is the complete hydrogeh'ation vof a material, `in which ease the ycontrol of the end point is relativ'ely 'simple and th'e temperature 'may be falwbd to T'i'se if desired.

degree 'of "reaction, or `cornpl'eteriress 'of hydrogerie-tion (fas measured 4from time to tim-'e by determining 'the iodine value, 'or the refractive index, 'or the 'eongeal point, or the titer., or 'other index, 'of samples fof 'the hydrogen'ated :liquid withdrawn from the system after the reaction has @eas-ed) may yconi/'entently be vcontrolled"by regulating the rate of introduction of the liquid to be -hydro'genated ns this liquid rate is varied Ione may simultaneously and 'correspondingly i/fary the rates "of feed 'of the catalyst slurry and the hydrogen, thus maintaining constant propere tions bf 'catalyst and hydrogen in relation to the lid-uid lfeed rate, "or one may alternatively lkeep one or both "oi these secondary feed iates constarrt, "or vary fit independently rof the liquid feed ifate, thus f'gaining -an independent or supplementary l'f'zontrol over the extent 'of the 'hydrogenation 'which occurs. The amount 'of hydrogen fs supplied to the hydrogenator 'should i'of course be adequate for -th'e degree of :hydro- -genation desired, I'and may conveniently 'be somewhat in excess of 'this amount in Yorder to 4insure utilizing :the maximum hydrogenating capacity of thehydrogenator.

vIlia'ving thus described our invention, Awhat we claim and desire to secure by Letters Patent is:

l. In 'apparatus for "continuous hydrogenation Vof `unsaturated liquids, the 'combination with an elongated generally cylindrical `Ahydrogenatiori Vessel lmember having inlet and outlet passages atopp'osite ends thereof, whereby hydrogen, 'a hyfd'rogenatin catalyst, and a liq'uid vto be treated may be passed 'through said vessel member, said vessel ibeing encircled by 'a Acooling jacket, of an agitator shaft vmember extending central-ly with- 8 in and :lengthwise of said vessel member and have. ing an outside diameter not less than half the internal diameter fof the vessel member, means journaling said shaft member jfor rotation, aplui rality 'of outwardly directed, axially spaced 'agitator blades carried by said shaft member, a plural- `ity 'of inwardly directed, axially spaced sta-tor blades carried by said vessel member, said stator blades extending between adjacent, axially Ispaced agitator blades, said stator and agitator blades` having the pressure surfaces thereof disposed generaliy axially 'of the vessel member and a pluL ral'ity 'of transverse baffle plates carried by one of said members and extending transversely and.

substantially .radially toward and into close proies ,imi-ty to the other of said Imembers to afford re .stricted passages therebetween, said baille plates being annular in for-m and being axially spaced to denne with said members a plurality of annuy,lar zones in restricted communication, whereby channeling of unhydrogenated liquid to the outlet of 'said vessel member is prevented.

2: Apparatus .as claimed in claim '1, in which saids-tator and agitator blades have an eiective width, measured radially of the vessel member, which is at least of the difference between the external radiusI 0f the agitator shaft andthe internal radius Iof the vessel. Y

33. VApparatus as claimed in claim 1, in which the axial spacing between adjacent agitator and stator yblades 'is not substantially in excess of 'that required for mechanical clearance. Y

4. Apparatus as claimed in claim 1, and comprising variable capacity pumping means adapted to iorce continuous controlled streams of unsatu rated liquid, of-hydrogenation catalyst slurry,an'd of hydrogen into "and through said Vessel meinber, and a heat exchanger for preheating said stream of liquid tohydrogenat'ing temperature.

VICTOR MILLS. JUDSON H. SANDERS. HAROLD HAWLEY.

`REFRENCES CITED The following references are 'of record fin :the le of this patent:

STAT-ES PATENTS 

1. IN APPARATUS FOR CONTINUOUS HYDROGENATION OF UNSATURATED LIQUIDS, THE COMBINATION WITH AN ELONGATED GENERALLY CYLINDRICAL HYDROGENATION VESSEL MEMBER HAVING INLET AND OUTLET PASSAGES AT OPPOSITE ENDS THEREOF, WHEREBY HYDROGEN, A HYDROGENATION CATALYST, AND A LIQUID TO BE TREATED MAY BE PASSED THROUGH AID VESSEL MEMBER, SAID VESSEL BEING ENCIRCLED BY A COOLING JACKET, OF AN AGITATOR SHAFT MEMBER EXTENDING CENTRALLY WITHIN AND LENGTHWISE OF SAID VESSEL MEMBER AND HAVING AN OUTSIDE DIAMETER NOT LESS THAN HALF THE INTERNAL DIAMETER OF THE VESSEL MEMBER, MEANS JOURNALING SAID SHAFT MEMBER FOR ROTATION, A PLURALITY OF OUTWARDLY DIRECTED, AXIALLY SPACED AGITATOR BLADES CARRIED BY SAID SHAFT MEMBER, A PLURALITY OF INWARDLY DIRECTED, AXIALLY SPACED STATOR BLADES CARRIED BY SAID VESSEL MEMBER, SAID STATOR BLADES EXTENDING BETWEEN ADJACENT, AXIALLY SPACED AGITATOR BLADES, SAID STATOR AND AGITATOR BLADES HAVING THE PRESSURE SURFACES THEREOF DISPOSE GENERALLY AXIALLY OF THE VESSEL MEMBER AND A PLURALITY OF TRANSVERSE BAFFLE PLATES CARRIED BY ONE OF SAID MEMBERS AND EXTENDING TRANSVERSELY AND SUBSTANTIALLY RADIALLY TOWARD AND INTO CLOSE PROXIMITY TO THE OTHER OF SAID MEMBERS TO AFFORD RE- 